Liquid dispensing apparatus



March 25, `1969 LIQUID DISPENSING APPARATUS Filed Jan. 25. 1967 sheet ofs ATTORNEY R. K. GELLATLY 3,434,634 i March 25, 1969 R. K. GELLATLY3,434,634

LIQUID DISPENSING APPARATUS Filed Jan. 25, 1957 sheet Z of s izo' :25

no `FWIIS E He .438 152` @Se se 'zo 25 A90 a@ a 114 '83 1223d v xof |76Y@ 12B INVENTOR ROBERT K. GELLATLY ATTORNEY March 25, 1969 R. K.GELLATLY 3,434,634

LIQUID DISPENS ING APPARATUS Filed Jan. 25, 1967 sheet 3 of 3 me i= @Jme S I 'I E E H2 88 l 8O Y 202 g 20A 20a f/-d HO INVENTOR. ROBERT K.GELLATLY ATTORNEY United States Patent Ofiice 3,434,634 LIQUIDDISPENSING APPARATUS Robert K. Gellatly, Santa Clara, Calif., assignorto FMC Corporation, San Jose, Calif., a corporation of Delaware FiledJan. 25, 1967, Ser. No. 611,629 Int. Cl. G01f 1.1/32; B65b 37/00 U.S.Cl. 222-450 6 Claims ABSTRACT F THE DISCLOSURE Cross reference torelated applications T he subject liquid dispensing apparatus isdesigned for use in a carton forming and filling machine of the typedisclosed in the pending application of Vadas et al., Ser. No. 461,73 8,and is an improvement of the dispensing apparatus disclosed in thepending application of Gellatly, Ser. No. 514,181 which issued on Aug.l5, 1967 as Patent No. 3,335,921, said applications both being assignedto the assignee of the present invention.

Background of the invention This invention pertains to liquid dispensingapparatus and more particularly relates to a positive displacementfilling apparatus having an improved foot valve for rapidly filling apredetermined quantity of liquid such as milk, into a container.

When filling cartons in excess of the rate of about 125 quart cartonsper minute with the type of filler disclosed in the above mentionedVadas et al. application, it has been noted that the milk tends to foambecause of the high velocity and turbulence imparted to the milk by therestriction caused by the foot valve in the valve body or filling tube.Experimental data also appears to indicate that the rapid opening of thefoot valve causes the milk to -ow out of the filling tube past the footvalve in the form of a large diameter tubular, as distinguished from acylindrical, stream of liquid, and that an air bubble is trapped withinthe tubular stream thereby increasing the tendency of the milk to foam.

Summary of the invention The dispensing apparatus of the presentinvention is designed to overcome the foaming problem by providing adouble-opening foot valve which initially opens a relatively smalldiameter central port in a sealing ring of the foot valve therebycausing the initial flow of milk to be in substantially the form of asmall diameter cylindrical stream through the central port thuspreventing the formation of a bubble therebelow. Thereafter the ring islifted from its seat in the filling tube to completely open the footvalve permitting a high volume, slow speed fiow of milk from the fillingtube past the outside surfaces of 3,434,634 Patented Mar. 25, 1969 thering as well as through the central port in the ring thereby greatlyreducing the velocity and turbulence at the foot valve, and accordingly,reducing the foaming tendency to a minimum.

Brief description of the drawings FIGURE 1 is a vertical central sectionof a turret upon which a plurality of dispensing apparatus-es of thepresent invention are mounted, only two dispensing apparatuses beingillustrated therein.

FIGURE 2 is an enlarged side elevation of one dispensing apparatus shownin its retracted position with the foot valve closed, a major portion ofthe apparatus being cut away to illustrate certain operative componentsin central vertical section.

FIGURE 3 is an enlarged vertical section of the foot valve takensubstantially along lines 3*.-3 of FIGURE 5 illustrating the valve inpartially open position.

FIGURE 4 is a section similar to FIGURE 3 but illustrating the footvalve in a fully open position.

FIGURE 5 is an enlarged horizontal section taken along lines 5-5 ofFIGURE 4 and illustrating the structure for centering the foot valvewithin the filling tube.

FIGURE 6 is an enlarged central section illustrating the variableorifice valve in solid lines in a position wherein the foot valve isclosed and in a phantom lined position wherein the foot valve is fullyopen.

FIGURE 7 is an enlarged central section similar to FIGURE `6 butillustrating a modified form of the invention in two operativepositions.

Description of preferred embodiment In general, each of a plurality ofliquid dispensing apparatus 10 (only two being shown in FIGURE 1) of thepresent invention is bolted to an outlet opening 12 of a liquid supplytank 14 which is supported upon the upper end of a turret 15. The turret15 comprises a stationary vertical column 16 which rotatably supportsthe tank 14 and a stabilizing wheel 17 near its upper end, and whichrotatably supports a sprocket 18 and a lower stabilizing wheel 19 nearits lower end. A continuously driven conveyor 20 is provided with evenlyspaced carriers 21 thereon. Each carrier is adapted to support a cartonC in alignment with an associated dispensing apparatus 10 as the cartonand the dispensing apparatus 10 is moved around the axis of the column16, which axis defines the axis of rotation of the turret 15. Thesprocket 18 is connected in driving engagement to the lower stabilizingwheel 19 by a drive post 22, and the lower stabilizing wheel 19 isconnected to the upper stabilizing wheel 17 and to the tank 14 by aplurality of evenly spaced vertically extending inner guide rods 23 anda plurality of evenly -spaced vertically extending outer guide rods 24.

As clearly shown on the right side of FIGURE 1, each dispensingapparatus is provided with two cam actuated arms 25 and 26 which areguided for vertical movement during the filling operation by one of therods 23 and by one of the rods 24. An upper nonrotatable cam 27 isrigidly secured to the stationary column 16 and cooperates with theupper arm 25 to vertically reciprocate a first portion of eachdispensing apparatus 10, and a. lower non-rotatable cam 28 is silmilarlysecured to the stationary column 16 and cooperates with the arm 26 tovertically reciprocate another portion of the dispensing apparatus 10. Alarge diameter foot valve latching cam ring 29 is mounted in fixedposition around the turret 15 outside the path of movement of eachdispensing apparatus -by one or more brackets 30 and by a utility post31, whcih brackets and post are rigidly secured to the frame of themachine. The cam ring 29 is not a truly circular member but includes asmall diameter arcuate portion 29a which holds a foot valve of theapparatus 10 closed, and a large diameter portion 29h which permitsopening of the foot valve during the filling operation.

It is to ybe understood that the specific details of the turret form nopart of the present invention. If a more detailed description of theturret and its actuating mechanism is desired reference may be had tothe aforementioned Vadas et al. application. It is also to be understoodthat the dispensing apparatus 10 need not be limited to turret mountedoperation as above described, but the apparatus 10 may be mounted infixed position and may cooperate with a conveyor which intermittentlyadvances cartons into and out of filling position.

Each liquid dispensingr apparatus 10 (FIG. 2) cornprises an uppertubular housing 66 having a flanged upper end 68 boltoed to andcommunicating with the tank 14 through one of the openings 12. Agenerally tubular inlet valve housing 70 has its upper end 70a disposedaround the lower end of the housing 66 and sealed thereto by a fiexiblesleeve 74 which permits vertical movement of the inlet valve housing 70relative to the upper housing 66. The lower reduced diameter end 70b ofthe inlet valve housing 70 is provided with an inlet valve 76 which isalternately moved between an open and a closed position by a camoperated actuated device 78. The upper end portion 80a of a generallytubular liquid measuring housing 80 is slidably received around thelower end portion 70b of the inlet valve housing 70 for verticalmovement relative thereto and is sealed thereto by an O-ring 81 and aflexible sleeve 82.

The O-ring 81, sleeve 82 and the adjacent wall of the end portions 80aand 70b define a vacuum chamber 83 which has a check valve 83acommunicating therewith that prevents air from entering the vacuumchamber but permits air to be forced therefrom. When the measuringhousing 80 moves downward the sleeve displaces substantially all the airfrom the vacuum chamber 83 through the check valve 83a. During movementof the inlet housing 70 and liquid measuring housing 80 in directionswhich cause the measuring chamber 88 to diminish in size, the checkvalve 83a prevents air from entering the vacuum chamber thus creating avacuum therein as the vacuum chamber enlarges. The vacuum causes theflexible sleeve 82 to fold and cling to the outer wall of the endportion 70b during the carton filling stroke thereby preventing anyvolume disturbing accordian folds from occurring in the flexible sleeve82 which would vary the quantity of liquid discharged -from theapparatus 10 during each filling stroke of the liquid dispensingapparatus.

The liquid measuring housing 80 includes a reduced diameter filling tube84 at its lower end, which filling tube is inserted into a carton C tobe filled and has the im- -proved double-opening foot valve 86 of thepresent invention at its lower end. The liquid measuring housing 80defines a variable capacity, volumetric liquid measuring chamber 88which is at all times filled with liquid. A valve actuating device 90 isoperatively connected to the foot valve 86 and responds to an increaseof pressure within the measuring chamber 88 to open the foot valve 86,the pressure increased in the chamber 88 caused by decreasing the sizeof the chamber 88 upon movement of the inlet valve housing 70 and theliquid measuring housing 80 toward each other after the inlet valve 76has first been closed.

The improved foot valve 86 (FIGS. 2 to 5) is of the inwardly openingtype and is disposed within the filling tube 84 for movement by theactuating device 90 between the closed position illustrated in FIGURE 2,the partially 4 open position illustrated in FIGURE 3, and the fullyopen position illustrated in FIGURE 4.

The foot valve 86 comprises a vertically elongated rod having its upperend pivotally connected to a lever 112 of the actuating device 90. Arelatively small diameter frusto-conical valve plug 114 is rigidlysecured to the lower end of the rod and has a narrow stop lug 116projecting upwardly therefrom. The foot valve also includes a valve cage118 having a generally tubular body 120 with a resilient sealing ring122 rigidly secured to its lower end. When the foot valve 86 is closed,the ring 122 rests on and seals against an inturned lip 123 of thefilling tube 84, and the plug 114 rests on and seals a central port 124in the ring 122.

The body 120 is provided with several elongated vertical slots 125 inits periphery, which slots permit the legs of a rod centering spider 126to pass therethrough. The centering spider 126 cooperates with an upperspider 128 and both spiders are rigidly secured to the rod 110 andslidably engage the inner cylindrical surface of the filling tube 84 tomaintain the rod 110 centered at all times.

As indicated in FIGURE 3, the stop lug 116 projects through one of threelower slots 130 in the body 120 and engages a horizontal edge 132 ofsaid one slot 130 after the rod 110 has been moved upwardly a sufficientdistance to space the plug 114 from the central port 124 in the ring 122thereby partially opening the foot valve. Further upward movement of therod 110 causes the entire cage 118 to move upwardly thereby completelyopening the foot valve 86 as indicated in FIGURE 4. During this movementof the cage 118, the cage is maintained centered by three equally spacedlegs 136 formed on a lower spider 138, and similar legs formed on anupper spider 140, both spiders being integrally formed on the cage 118.

In order to prevent chattering of the foot valve during filling, avariable orifice valve 144 (FIG. 2) is provided in the inlet end of thefilling tube 84, which valve 144 cooperates with the foot valve 86. Thevariable orifice valve 144 and foot valve 86 cooperate to eliminatechattering of the foot valve during both a relatively slow preliminaryfilling operation and a nal rapid filling operation by assuring thatsufficient back pressure is retained in the measuring chamber 88 againstthe valve actuating device 90 during both preliminary and final filling,and by assuring that the flow passages within the dispensing housing aresufficiently open during both preliminary and final lling to accommodatethe rate of liquid flow therethrough without a loss of accuracy as tothe quantity of liquid being discharged into the cartons.

The variable orifice valve 144 comprises an orifice plate 146 (FIG. 2)which includes an annular flange 148 formed integrally with an annulardish 150 that is inclined downwardly toward a central circular orifice152. The orifice plate 146 is loosely fitted into the upper end of thefilling tube 84 and has the upper end of the foot valve actuating rod110 of the foot valve 86 extending therethrough.

A cylindrical valve head of substantial length is secured to the rod 110and is disposed in partially closed or an orifice restricting positionin the orifice 152 when the foot valve 86 is in both the closed andpartially open positions. It has been found that a radial clearance ofbetween 15-30 thousandths of an inch is necessary between the walls ofthe orifice 152 and the periphery of the valve head 160 to assure that asufficient build up of pressure in the portion of the measuring chamber88 above the Orifice valve 144, will occur, even at slow filling speeds,to fully open the foot valve, and yet will permit a limited amount ofthe liquid to flow past the orifice valve 144 permitting this limitedamount of liqud to How out of the foot valve 86 initially through theport 124 in the ring and thereafter through the port as well as aroundthe outer periphery of the ring. It will be noted that the thickness ofthe valve head 160 is sufficient to remain within the orifice 152 whenthe valve is closed and will remain in the orifice until after the footvalve is completely opened as indicated in FIGURE 4.

As indicated previously, the movement of the inlet valves 7'6 iscontrolled by the actuating device 78 which includes a movable lever 172that is pivotally supported by the inlet valve housing 70 at 174 and issealed to the hous` ing by a flexible diaphragm 176. One end of thelever 172 is pivotally connected to a vertically extending actuating rod178 of the inlet valve 76. A cam follower 180 is journalled on anotherportion of the lever 172 and rides along a lower camming surface 182 ofthe cam 27. The inlet valve 76 is normally held in a closed position bya spring 184 connected between the lever 172 and the inlet valve housing70 and is opened in response to the cam follower 180 riding along araised arcuate lobe 183 on the camming surface 182.

Since the construction of the foot valve actuating device 90 issubstantially the same as that of the inlet valve actuating device 78,the device 90 will not be described in detail. It will be noted now,however, that the lever 112 is pivoted to the measuring housing 80 at186 and that the foot valve 86 is positively held closed by the smalldiameter portion 29a (FIG. 1) of the cam ring 29 during a portion of acycle of operation of the turret and is opened by a build up of pressurewithin the measuring chamber 88 as the device 80 moves through thearcuate range of the large diameter portion of the ring 2,9.

The inlet housing 70 is vertically reciprocated by an upper flange 188of the cam 27, which flange engages a cam follower 190 journalled on theupper arm 25. The measuring housing 80 is vertically reciprocatedrelative to the inlet housing 70 and relative to the carton C to belilled by a flange 192 on the cam 28 which engages a cam follower 194journalled on the arm 26.

At the beginning of the cycle of operation of the liquid dispensingapparatus of the present invention, the components of the apparatus arepositioned as shown in FIGURE 2 with a carton C to be filled beingsupported by a carrier 21 directly below the associated filling tube 84.As illustrated in FIGURE 2, the inlet valve 76 is held open by the camfollower 180 of the valve actuating device 78 `which engages anactuating lobe 183 on the annular cam 27, which cam is concentric withthe vertical axis of rotation of the turret-supported liquid supply tank14. At this time, the cam follower 190` that is journalled on the arm 25holds the inlet valve housing 70 in its uppermost position by ridingalong the upper iiange 188 of the cam 27. The cam follower 194 on theend of the arm 26 rides along the ange 192` of the annular cam 28, whichcam includes adjustable portions (not shown) that may be verticallyadjusted so as to control the vertical travel of the measuring housing.Thus, -when it is desired to fill different size cartons withpredetermined quantities of liquid, both the adjustable portion of thecam 28 and the vertically adjustable carton carrier 21 are raised orlowered to the desired vertical positions by means fully disclosed inthe Vadas et al. application.

In order to positively hold the foot valve 86 closed dur ing the periodwhen the inlet valve 7-6 is opened, latching means such as the annularcam ring 29 is positioned outwardly of the apparatus 10 and engages aportion of the valve actuating device 90 to positively hold the footvalve closed at all times when the inlet valve 76 is open. When theinlet valve is closed, the actuating device 90 enters the portion 29b ofthe ring 29 permitting the valve 86 to open. The portion 29b also servesto limit the maximum amount of opening permitted the foot Valve 86. Itwill also be understood that when the inlet valve 76 is closed,atmospheric pressure acting on the external surfaces of the actuatingdevice 90 will be greater than the negative pressure within themeasuring chamber 88 and will hold the foot valve 86 closed until thehousings 70 and 80 are moved toward each other to provide a positivepressure Within the measuring chamber 88 that is greater than thepressure outside the chamber. In this regard the O-ring 81 and checkvalve 83a prevent atmospheric pressure from acting on the sleeve 82, andaccordingly, a negative pressure Iwill be present within the vacuumchamber 83 and measuring chamber 88 upon any movement which tends toenlarge the measuring chamber 88. It will be understood that the camtrack 29 is sufiiciently tall to maintain a position in horizontalalignment with the actuating device 90.

Upon rotation of the liquid supply tank 14 and liquid dispensingapparatus 10 about the cams 27 and 28, the measuring housing 80 is firstlowered to draw liquid through the open inlet valve 76 into themeasuring chamber 88 of the liquid measuring housing 80, and to move thefilling tube 84 into the carton with its lower end disposed immediatelyadjacent, i.e., about lV16 to 3/8 of an inch, from the bottom closure ofthe carton. The inlet valve 76 is then closed in response to the camfollower 180 moving off the lobe 183 of the cam 27. With the inlet valveclosed and the actuating mechanism 90 released, continued rotation ofthe dispensing apparatus 10v about the vertical turret axis causes theinlet valve housing to gradually lower, thereby increasing the pressurein the measuring chamber 88 and causing the foot valve 86 to firstpartially open as indicated in FIGURE 3 and immediately thereafter tofully open as indicated in FIGURE 4, permitting liquid to relativelyslowly enter the carton during a prefilling operation to a depthslightly above that of the lower end of the iilling tube. The annularcam 28 then rapidly raises the measuring housing 80 while the housing 70is held 4from vertical movement, thereby rapidly reducing the volume ofthe measuring chamber 88 and causing the liquid therein to rapidly flowthrough the filling tube into the carton.

After the carton has been filled with the desired quantity of liquid andthe lower end of the filling tube 84 is within the liquid in the carton,relative motion between the inlet housing 70 .and the measuring housing80 ceases, thus again establishing the aforementioned negative pressurewithin the measuring chamber causing the foot valve 86 to close. Afterthe 4foot valve has closed, the cams 27 and 28 raise the inlet housing70 and measuring housing 80 as a unit thereby withdrawing the fillingtube from the carton. Shortly after the foot valve has been closed bynegative pressure within the measuring chamber 88, the actuating device90 enters the small diameter arcuate portion 29a of the latching ring 29thereby latching the foot valve 86 closed until the cycle of operationis completed.

As mentioned previously, the rapid opening of the foot valve tends todraw a bubble of air within the stream of liquid being discharged lfromthe filling tube. However, in accordance with the present invention, thedouble opening valve eliminates this problem by first lifting the plug114 away from the central port 124 in the ring 122 thereby causing theinitial stream of liquid Abeing discharged from the filling tube to bein the form of a cylindrical stream of liquid, as opposed to a tubularstream of liquid, thus preventing the entrapment of any measurableamount of a1r within lboundaries defined by the owing liquid. Thevariable orifice valve 144 (FIGS. 2 -and 6) is arranged to effect thefull opening of the foot valve immediately after the initial raising ofthe plug 114 even during the slow filling rates and pressures whichoccur during the prefilling operation.

After the liquid discharged into the carton has risen to a heightslightly above the lower end of the filling tube 84, the pressure withinthe chamber 88 is increased due to the rapid upward movement of themeasuring housing 80, causing the orifice valve head to raise above theorice 152 permitting a large volume of liquid to flow pastv the orificeplate 146 while maintaining sufficient pressure on the valve actuatingdevice 90 to hold the foot valve completely open and to preventchattering of the same. With the foot valve 86 completely opened asindicated in FIGURE 4, the remaining portion of the carton can be veryrapidly filled without danger of foaming or excess turbulence occurringat the discharge end of the filling tube since the flow passagesexternally of the ring 122 and through the central port 124 of the footvalve are sufiiciently large to minimize turbulence.

It will be appreciated that the varia-ble orifice valve 1 44 cooperateswith the foot valve 86 to control the openlng of the foot valve so thatthe initial ow of fluid out of the foot valve will be through thecentral port 124 and so that the foot valve will move to the fully openposition immediately thereafter even if the pressure within themeasuring chamber 88 is low as is the case when the size of the chamber88- is slowly reduced during the prefill operation.

As mentioned above, the variable orifice valve 144 includes acylindrical valve head 160 which is sufficiently long to remain withinthe orifice 152 until after both the plug 114 and ring 122 have beenmoved to positions which fully open the foot valve 86. Thus, in thepreferred embodiment of the invention the ring 122 moves away from thelip 123 immediately after the plug 114 has moved `away from the ring 122to fully open the valve even in response to a low pressure within themeasuring chamber 88.

In the embodiment of the invention illustrated in FIG- URE 7 a vari-ableorifice valve 200 is disclosed which causes the foot valve 86 to opendifferent amounts as determined by the pressure within the measuringchamber 88. The orice valve 200 may be substituted for the valve 144 andis identical to the valve 144 except that a frustoconical valve head 202is provided rather than the cylindrical valve head 160. As indicated inFIGURE 7, the valve head includes a narrow cylindrical upper portion 204which is loosely fitted within the orifice 206 so as t provide thedesired -30 thousandth of an inch therebetween which is necessary toprovide the initial valve opening pressure. As the valve head 202 andfoot valve moves upwardly in response to an increase of pressure withinthe measuring chamber 88, a frusto-conical portion 208 of the valve head202 enters the orifice 206 thereby increasing the clearance between theorifice and the valve head 202 permitting the liquid to more rapidlyfiow past the variable orifice valve 200 thereby reducing the pressurein cham-ber 88 and lowering the valve head 202 and ring 122 of the footvalve 86. Lowering of the ring 122 causes the fiow passage between thering 122 and lip 123 to be restricted in size.

Thus, the use of a frusto-conieal valve head 202 within the orifice isutilized to regulate the size 0f the fiow passages through the footvalve in direct proportion to pressure charges within the measuringchamber. It is also t0 be understood that the cylindrical upper portion204 can be omitted or be wider or narrower than illustrated so as tocontrol the amount of upward movement permitted of the valve head 202before the pressure control of the frusto-conical portion 208 begins totake effect.

Although the preferred embodiment of the invention illustrates adouble-opening valve, it will be understood that the invention is to beconsidered broad enough to cover a multiple-opening valve whereinadditional rings are disposed between the ring 122 and the lip 123 andare interconnected so that each ring can be lifted from the nextfollowing ring in step-by-step progression during opening of the valve.

From the foregoing description it will be apparent that the liquiddispensing apparatus of the present invention includes a double-openingfoot valve which is -first partially opened to direct a solid stream ofliquid centrally through the valve thereby preventing the entrapment ofan air bubble within the liquid, and immediately thereafter, under thecontrol of the variable orifice valve, further opens the foot valve toreinforce the central cylindrical stream with an outer stream therebyproviding a very large exit area so that a large quantity of liquid willfiow past the foot valve at a relatively slow speed thereby minimizingturbulence with the result that foaming is reduced to a minimum. Theapparatus also includes a pressure responsive variable orifice valvewhich controls the opening of the foot valve so that full opening of thefoot valve occurs immediately after partial opening thereof even at verylow operating pressures.

Although the best mode contemplated for carrying out the presentinvention has been herein shown and described, it will be apparent thatmodification and variation may be made without departing from what isregarded to be the subject matter of the invention as set forth in theappended claims.

Having completed a detailed description of the invention so that thoseskilled in the art could practice the same, I claim:

1. In a liquid dispensing apparatus comprising means defining a variablecapacity liquid measuring chamber which includes a filling tube havingan inlet end and an outlet end; means for filling said chamber with aquantity of liquid; means defining a double-opening valve movablebetween a closed position, a partially open position permitting acentrally disposed relatively small diameter substantially cylindricalstream of liquid to ow through the outlet end of the filling tube, and afully opened position permitting a large diameter stream of liquid tofiow through the outlet end of the filling tube and to supplement thesmall diameter cylindrical stream; means for decreasing the size of saidliquid measuring chamber thereby increasing the pressure within saidchamber; valve opening means in said measuring chamber connected to saidvalve for controlling the position of said valve; said double-openingvalve being a foot valve; means defining an orifice valve at the inletend of said filling tube, means defining an orifice in said orificevalve, an orifice `valve head associated with said orifice and having arelatively small clearance when disposed fully within said orifice, saidorifice `valve head being movable between a partially closed positionand an open position to vary the size of said orice from a substantiallyclosed restricted condition to a substantially unrestricted opencondition, and means connecting said orifice valve head to said footvalve to open both of said valves simultaneously.

2. An apparatus according to claim 1 wherein said orifice 4valve headincludes a large diameter cylindrical portion which remains within saidorifice until after the foot valve has been moved from the closed to thefully open position.

3. An apparatus according to claim 1 wherein said orifice valve headincludes a frusto-conical portion and wherein said frusto-conicalportion enters said orifice after the foot valve has first moved fromthe closed position to the partially open position.

4. An apparatus according to claim 1 wherein said means for decreasingthe size of said liquid measuring chamber decreases said chamber size atvariable rates thereby varying the pressure within said chamber, andwherein said means for opening the foot valve controls the amount ofopening of said orifice valve and said foot valve in direct proportionto the pressure changes in said measuring chamber.

5. An apparatus according to claim 1 wherein said means for decreasingthe size of said liquid measuring chamber decreases said chamber size atvariable rates thereby varying the pressure within said chamber, whereinsaid orifice valve head includes a large cylindrical portion whichremains within said orifice until after the foot 9 10 Valve has beenmoved from the closed to the fully open References Cited position, andwherein said means for opening the foot UNITED STATES PATENTS valvefully opens the foot valve at low pressures and re- 519,307 5 /1894Perkins 141 128 tains said foot valve at said fully open positionindepend- 3,128,915 4/ 1964 Matter 222-355 ently of pressure variationsin said chamber that are 5 3,295,722 1/1957 Gordon et 211 222-52 greaterthan Said 10W presslfre' ROBERT B. REEVES, Primary Examiner.

6. An apparatus according to clalm 5 wherein the clearance between saidorice and said orifice valve when H S LANE Asslstam Examiner in thepartially closed position is between about 15-30 10 US @1 XR.thousandths of an inch. 141-147

